Interesting things from the Plan 9 rc manpage

[Chris Siebenmann <cks>]

 $" is the Plan 9 rc syntax for Byron's $^ string flattening operator.
 'if not' is still there.
 The Plan 9 rc has a number of interesting options:
	-s:	Print out exit status after any command where the
		status is non-null (false).
	-I:	Do not run interactively, regardless of whether or
		not standard input is attached to a terminal.
 -p is listed as a no-op; presumably no one has bothered implementing
it.
 There's a 'flag' builtin that lets you test, set, and clear the
status of command-line flags.

 The manual page doesn't have a FILES section, so I don't know if the
Plan 9 rc has abandoned the 'source a file on startup' approach (the
copy of Duff's rc I have sources a file, but it's moderately old).

 Interestingly, one of the entries in the BUGS section is
	It's too slow and too big.
(as well as
	There should be a way to match patterns against whole lists
	rather than just single strings.
which I think some people here have wanted in the past.)

	- cks